Weired behaviour while we compile PL/SQL package

Question

Hi All,
We have one package where we have declared few constants those we are using all over our application code. By mistake, one of the developer declared one constant twice, we didn't notice it until today while chasing down a bug...
I was under impression that we can not declare same variable or constants twice in the same package/procedure/block. But surprisingly, if we are not using the same variable in that block, (We defined it global packaged constant) we are not getting compilation error or warning. Does anyone know anything about this.
Oracle Configuration:
Oracle9i Enterprise Edition Release 9.2.0.1.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - ProductionThanks in advance.
Thanks,
Dharmesh Patel

Answer 1

I would again point out that I do not see the results as you describe. see the output from 9.2.0.3 below. Both times it gives me the same result.
As shown above by James, it throws out the correct error under 10G. But as far as I see, it seems to be consistent under Oracle9i release 9.2.0.3 and 9.2.0.5.
I think it might be the time for your database to be upgraded to at least 9.2.0.3 release.
SQL> CREATE OR REPLACE PACKAGE P00_Constants AS
  2      SubType201 CONSTANT VARCHAR2(3) := '201';
  3      SubType202 CONSTANT VARCHAR2(3) := '202';
  4      SubType202A CONSTANT VARCHAR2(4) := '202A';
  5      SubType202P CONSTANT VARCHAR2(4) := '202P';
  6      SubType202I CONSTANT VARCHAR2(4) := '202I';
  7      SubType203 CONSTANT VARCHAR2(3) := '203';
  8      SubType201 CONSTANT VARCHAR2(3) := '204';
  9
10      Yesflag CONSTANT VARCHAR2(3) := 'YES';
11      ------------------------------------------------------
12
13      --- <summary>This function returns value of YES</summary>
14      --- <param name="none"></param>
15      --- <exception cref="none"> </exception>
16      FUNCTION GetyesFlag RETURN VARCHAR2;
17      PRAGMA RESTRICT_REFERENCES(GetYesFlag,
18                                 WNDS,
19                                 WNPS);
20  END P00_Constants;
21  /
Package created.
SQL> SHOW ERRORS
No errors.
SQL>
SQL> CREATE OR REPLACE PACKAGE BODY P00_Constants AS
  2      ---function getYesFlag
  3      FUNCTION GetYesFlag RETURN VARCHAR2 IS
  4      BEGIN
  5          RETURN YesFlag;
  6      END;
  7  END P00_Constants;
  8  /
Package body created.
SQL> SHOW ERRORS
No errors.
SQL>
SQL> CREATE OR REPLACE PACKAGE Test_Constant IS
  2      -- Author  : DPATEL
  3      -- Created : 10/12/2004 8:20:12 AM
  4      -- Purpose : To test the duplicate constants defined in P00_Constants package
  5      -- Public type declarations
  6      FUNCTION getSubType RETURN VARCHAR2;
  7  END Test_Constant;
  8  /
Package created.
SQL> SHOW ERRORS
No errors.
SQL>
SQL> CREATE OR REPLACE PACKAGE BODY Test_Constant IS
  2      FUNCTION getSubType RETURN VARCHAR2 IS
  3          mySubType VARCHAR2(10);
  4      BEGIN
  5          mySubType := P00_Constants.SubType201;
  6          RETURN(mySubType);
  7      END;
  8  END Test_Constant;
  9  /
Package body created.
SQL> SHOW ERRORS
No errors.
SQL>
SQL> -- Test Script
SQL> SET SERVEROUTPUT ON
SQL> BEGIN
  2      Dbms_OutPut.Put_Line('Result is: ' || test_constant.getsubtype);
  3  END;
  4  /
Result is: 204
PL/SQL procedure successfully completed.
SQL> ALTER PACKAGE P00_Constants COMPILE
  2  /
Package altered.
SQL> SET SERVEROUTPUT ON
SQL> BEGIN
  2      Dbms_OutPut.Put_Line('Result is: ' || test_constant.getsubtype);
  3  END;
  4  /
Result is: 204
PL/SQL procedure successfully completed.
SQL>
SQL> disconnect
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.3.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.3.0 - Production
SQL>